In all other cases wet chemistry

Table 10 presents a comparison
of all vegetation samples that showed

provided a more sensitive measure

positive

of 28] a concentration than did gamma

tam via gamma spectrometry.

This limited data set of five samples

spectrometry.

exhibits a mean MCL:LLL ratio of

increases in sensitivity were in the

0.95 + 22%, with no evidence for

range of 2.1- to 637-fold.

significant bias.

samples exhibited increases in the

Wet-chemistry

results are the simple averages of the

For vegetation samples,
Animal

range of 1.2- to 7,4-fold.

individual determinations by carrier
and carrier-free dissolution procedures.

WET-CHEMISTRY ANALYSES OF 241 VS

As indicated earlier in the

239,240

section on quality control, wetchemistry determinations of 24 sn

Pu

Results for 28 an and 239,240),

in vegetation may be systematically

were compared in those samples selected

low.

for wet chemistry.
Concentration
241
239

In addition, the large uncer-

tainties in the individual gamma

ratios of

measurements provide for a very

23942405, were calculated.

broad range of possible ratios.

Thus,

Am to

Pu and to

The

purposes of these computations were

there is no reason to conclude that

to examine any differences between

there is any significant difference

sample types

between wet chemistry and gamma
1 Am in
. vegetation.
,
spectrometry of

and sampling location (Bikini vs

(soil vs vegetation)

Eneu), and to determine mean ratios
-

Table 10,

Master log
number

01-0639-10

»

Comparison of a-PHA and gamma-spectrometric analyses for
vegetation (MCL vs LLL) .?

a-PHA
(MCL) dpm/g

Gamma spectrometry
(LLL), dpm/g

41am in

MCL:LLL

01-0641-10

0.44410

0.75419

0.34430%

1.3 432%

0.91455

0.82258

01-0803-10

4.9 +17

6.1 +20

0.80426

01-0829-10

0.43411

0.51456

0.84157

01~-0850-10

1.674 5.2

1.6 +30

1.0 +30

Average
a

All results are reported to a reference time of 1 January 1975

-~19-

|

0.951224
(001.0002,

75).

Select target paragraph3